这是问题是一个网友遇到的问题：一个UPDATE语句产生的共享锁阻塞了其他会话的案例，对于这个案例，我进一步分析、总结和衍化了相关问题。下面分析如有不对的地方，敬请指正。下面是初始化环境和数据的脚本。
--
-- Table structure for table `tableA`
--
DROP TABLE IF EXISTS `tableA`;
CREATE TABLE `tableA` (
`id` varchar(10) NOT NULL,
`name` varchar(10) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;
--
-- Dumping data for table `tableA`
--
LOCK TABLES `tableA` WRITE;
INSERT INTO `tableA` VALUES ('1','11'),('2','22');
UNLOCK TABLES;
--
-- Table structure for table `tableB`
--
DROP TABLE IF EXISTS `tableB`;
CREATE TABLE `tableB` (
`id` varchar(10) NOT NULL,
`bill_id` varchar(10) DEFAULT NULL,
`update_time` bigint(12) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `idx_bill_id` (`bill_id`)
) ENGINE=InnoDB;
--
-- Dumping data for table `tableB`
--
LOCK TABLES `tableB` WRITE;
/*!40000 ALTER TABLE `tableB` DISABLE KEYS */;
INSERT INTO `tableB` VALUES ('100','1',1586880000000),('200','2',1586793600000),('300','2',1586880000000),('400','2',1586880000000),('500','3',1586990000000),('600','4' ,1586990000000);
/*!40000 ALTER TABLE `tableB` ENABLE KEYS */;
UNLOCK TABLES;